The present invention relates broadly to transportation systems and, in particular, concerns a new and improved construction of guiding or guide apparatus for the travel elements of endless conveyors, such as escalators and the like, wherein main and follower rails are secured to a support or carrier frame by means of rail or track holders.
With such type of guide equipment the travel elements are supported and guided along an endless path of travel or track, and there is intended to obtain travel of such travel elements with as little noise and vibrations as possible. In the environment of escalators the guide apparatuses also serve the purpose of horizontally guiding the tread or walk surface of the travel or running elements constructed as stair steps during passage of the upper run both in horizontal direction as well as at the ascending region and at the transition locations.
German Patent Publication No. 2,157,423 discloses an escalator construction of the aforementioned type. More specifically, with this prior art system there are used special precision templets for the exact setting or adjustment of the travel or track rails. These precision templets contain alignment holes and by virtue of an appropriate machining process assure for parallelism and alignment of the travel rails or tracks with sufficient accuracy. For the assembly, the rail elements are held in a rigid or fixed mutual correlation by means of the templets and are connected with the same by performing precision welding.
Such assembly or erection procedures are complicated and afflicted with the known drawbacks which prevail when employing welding techniques: firstly, an appreciable expenditure in both equipment and work is needed for the welding together of the guide system in an accurate fashion, so that such assembly work cannot be considered to be capable of being performed rapidly and economically. Additionally, notwithstanding this appreciable effort it is impossible to guarantee for synchronous running of the travel elements to the required degree. This is so because even when performing precision welding distortions in the structure arise because of the introduction of heat or thermal energy during the welding process. This distortion can only be eliminated in part by subsequent cold and hot straightening.
Furthermore, with such assembly or erection concept it is necessary to use structural elements of the most different design and dimensions which are related to the system which is being erected. The employment of individual parts which have been fabricated in large series or mass-produced, which can be used for a wide range of installations in the form of similar type standardized parts generally is not possible.
Moreover, when the erection and assembly work is carried out by welding the travel rails or tracks which have become worn generally are difficult to dismantle, or, in fact, are connected in a non-releasable fashion with the support or carrier frame. Hence, there is not present any possibility of subjecting these worn tracks or travel rails, independent of the carrier frame, to a surface treatment or, whenever such travel rails have experienced excessive wear to rapidly and easily exchange the same.